Add Support for Highlight Wildcard in SQL

core/src/main/java/org/opensearch/sql/analysis/Analyzer.java

@@ -313,7 +313,6 @@ public LogicalPlan visitProject(Project node, AnalysisContext context) {
     for (UnresolvedExpression expr : node.getProjectList()) {
       HighlightAnalyzer highlightAnalyzer = new HighlightAnalyzer(expressionAnalyzer, child);
       child = highlightAnalyzer.analyze(expr, context);
-
     }
 
     List<NamedExpression> namedExpressions =

core/src/main/java/org/opensearch/sql/analysis/ExpressionAnalyzer.java

@@ -205,7 +205,7 @@ public Expression visitWindowFunction(WindowFunction node, AnalysisContext conte
   }
 
   @Override
-  public Expression visitHighlight(HighlightFunction node, AnalysisContext context) {
+  public Expression visitHighlightFunction(HighlightFunction node, AnalysisContext context) {
     Expression expr = node.getHighlightField().accept(this, context);
     return new HighlightExpression(expr);
   }

core/src/main/java/org/opensearch/sql/analysis/HighlightAnalyzer.java

@@ -30,12 +30,13 @@ public LogicalPlan analyze(UnresolvedExpression projectItem, AnalysisContext con
 
   @Override
   public LogicalPlan visitAlias(Alias node, AnalysisContext context) {
-    if (!(node.getDelegated() instanceof HighlightFunction)) {
+    UnresolvedExpression delegated = node.getDelegated();
+    if (!(delegated instanceof HighlightFunction)) {
       return null;
     }
 
-    HighlightFunction unresolved = (HighlightFunction) node.getDelegated();
+    HighlightFunction unresolved = (HighlightFunction) delegated;
     Expression field = expressionAnalyzer.analyze(unresolved.getHighlightField(), context);
-    return new LogicalHighlight(child, field);
+    return new LogicalHighlight(child, field, unresolved.getArguments());
   }
 }

core/src/main/java/org/opensearch/sql/ast/AbstractNodeVisitor.java

@@ -261,7 +261,7 @@ public T visitAD(AD node, C context) {
     return visitChildren(node, context);
   }
 
-  public T visitHighlight(HighlightFunction node, C context) {
+  public T visitHighlightFunction(HighlightFunction node, C context) {
     return visitChildren(node, context);
   }
 }

core/src/main/java/org/opensearch/sql/ast/dsl/AstDSL.java

@@ -272,8 +272,9 @@ public When when(UnresolvedExpression condition, UnresolvedExpression result) {
     return new When(condition, result);
   }
 
-  public UnresolvedExpression highlight(UnresolvedExpression fieldName) {
-    return new HighlightFunction(fieldName);
+  public UnresolvedExpression highlight(UnresolvedExpression fieldName,
+      java.util.Map<String, Literal> arguments) {
+    return new HighlightFunction(fieldName, arguments);
   }
 
   public UnresolvedExpression window(UnresolvedExpression function,

core/src/main/java/org/opensearch/sql/ast/expression/HighlightFunction.java

@@ -6,6 +6,7 @@
 package org.opensearch.sql.ast.expression;
 
 import java.util.List;
+import java.util.Map;
 import lombok.AllArgsConstructor;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
@@ -21,10 +22,11 @@
 @ToString
 public class HighlightFunction extends UnresolvedExpression {
   private final UnresolvedExpression highlightField;
+  private final Map<String, Literal> arguments;
 
   @Override
   public <T, C> T accept(AbstractNodeVisitor<T, C> nodeVisitor, C context) {
-    return nodeVisitor.visitHighlight(this, context);
+    return nodeVisitor.visitHighlightFunction(this, context);
   }
 
   @Override

core/src/main/java/org/opensearch/sql/expression/HighlightExpression.java

@@ -5,10 +5,16 @@
 
 package org.opensearch.sql.expression;
 
+import java.util.LinkedHashMap;
 import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import lombok.Getter;
 import org.opensearch.sql.common.utils.StringUtils;
+import org.opensearch.sql.data.model.ExprTupleValue;
 import org.opensearch.sql.data.model.ExprValue;
+import org.opensearch.sql.data.model.ExprValueUtils;
 import org.opensearch.sql.data.type.ExprCoreType;
 import org.opensearch.sql.data.type.ExprType;
 import org.opensearch.sql.expression.env.Environment;
@@ -20,6 +26,7 @@
 @Getter
 public class HighlightExpression extends FunctionExpression {
   private final Expression highlightField;
+  private final ExprType type;
 
   /**
    * HighlightExpression Constructor.
@@ -28,6 +35,8 @@ public class HighlightExpression extends FunctionExpression {
   public HighlightExpression(Expression highlightField) {
     super(BuiltinFunctionName.HIGHLIGHT.getName(), List.of(highlightField));
     this.highlightField = highlightField;
+    this.type = this.highlightField.toString().contains("*")
+        ? ExprCoreType.STRUCT : ExprCoreType.ARRAY;
   }
 
   /**
@@ -37,21 +46,57 @@ public HighlightExpression(Expression highlightField) {
    */
   @Override
   public ExprValue valueOf(Environment<Expression, ExprValue> valueEnv) {
-    String refName = "_highlight" + "." + StringUtils.unquoteText(getHighlightField().toString());
-    return valueEnv.resolve(DSL.ref(refName, ExprCoreType.STRING));
+    String refName = "_highlight";
+    // Not a wilcard expression
+    if (this.type == ExprCoreType.ARRAY) {
+      refName += "." + StringUtils.unquoteText(getHighlightField().toString());
+    }
+    ExprValue value = valueEnv.resolve(DSL.ref(refName, ExprCoreType.STRING));
+
+    // In the event of multiple returned highlights and wildcard being
+    // used in conjunction with other highlight calls, we need to ensure
+    // only wildcard regex matching is mapped to wildcard call.
+    if (this.type == ExprCoreType.STRUCT && value.type() == ExprCoreType.STRUCT) {
+      value = new ExprTupleValue(
+          new LinkedHashMap<String, ExprValue>(value.tupleValue()
+              .entrySet()
+              .stream()
+              .filter(s -> matchesHighlightRegex(s.getKey(),
+                  StringUtils.unquoteText(highlightField.toString())))
+              .collect(Collectors.toMap(
+                  e -> e.getKey(),
+                  e -> e.getValue()))));
+      if (value.tupleValue().isEmpty()) {
+        value = ExprValueUtils.missingValue();
+      }
+    }
+
+    return value;
   }
 
   /**
    * Get type for HighlightExpression.
-   * @return : String type.
+   * @return : Expression type.
    */
   @Override
   public ExprType type() {
-    return ExprCoreType.ARRAY;
+    return this.type;
   }
 
   @Override
   public <T, C> T accept(ExpressionNodeVisitor<T, C> visitor, C context) {
     return visitor.visitHighlight(this, context);
   }
+
+  /**
+   * Check if field matches the wildcard pattern used in highlight query.
+   * @param field Highlight selected field for query
+   * @param pattern Wildcard regex to match field against
+   * @return True if field matches wildcard pattern
+   */
+  private boolean matchesHighlightRegex(String field, String pattern) {
+    Pattern p = Pattern.compile(pattern.replace("*", ".*"));
+    Matcher matcher = p.matcher(field);
+    return matcher.matches();
+  }
 }

core/src/main/java/org/opensearch/sql/expression/function/OpenSearchFunctions.java

@@ -17,7 +17,6 @@
 import org.opensearch.sql.data.type.ExprType;
 import org.opensearch.sql.expression.Expression;
 import org.opensearch.sql.expression.FunctionExpression;
-import org.opensearch.sql.expression.HighlightExpression;
 import org.opensearch.sql.expression.NamedArgumentExpression;
 import org.opensearch.sql.expression.env.Environment;
 
@@ -37,15 +36,6 @@ public void register(BuiltinFunctionRepository repository) {
     repository.register(match_phrase(BuiltinFunctionName.MATCH_PHRASE));
     repository.register(match_phrase(BuiltinFunctionName.MATCHPHRASE));
     repository.register(match_phrase_prefix());
-    repository.register(highlight());
-  }
-
-  private static FunctionResolver highlight() {
-    FunctionName functionName = BuiltinFunctionName.HIGHLIGHT.getName();
-    FunctionSignature functionSignature = new FunctionSignature(functionName, List.of(STRING));
-    FunctionBuilder functionBuilder = arguments -> new HighlightExpression(arguments.get(0));
-    return new DefaultFunctionResolver(functionName,
-        ImmutableMap.of(functionSignature, functionBuilder));
   }
 
   private static FunctionResolver match_bool_prefix() {

core/src/main/java/org/opensearch/sql/planner/logical/LogicalHighlight.java

@@ -6,20 +6,28 @@
 package org.opensearch.sql.planner.logical;
 
 import java.util.Collections;
+import java.util.Map;
 import lombok.EqualsAndHashCode;
 import lombok.Getter;
 import lombok.ToString;
+import org.opensearch.sql.ast.expression.Literal;
 import org.opensearch.sql.expression.Expression;
 
 @EqualsAndHashCode(callSuper = true)
 @Getter
 @ToString
 public class LogicalHighlight extends LogicalPlan {
   private final Expression highlightField;
+  private final Map<String, Literal> arguments;
 
-  public LogicalHighlight(LogicalPlan childPlan, Expression field) {
+  /**
+   * Constructor of LogicalHighlight.
+   */
+  public LogicalHighlight(LogicalPlan childPlan, Expression highlightField,
+      Map<String, Literal> arguments) {
     super(Collections.singletonList(childPlan));
-    highlightField = field;
+    this.highlightField = highlightField;
+    this.arguments = arguments;
   }
 
   @Override

core/src/main/java/org/opensearch/sql/planner/logical/LogicalPlanDSL.java

@@ -63,8 +63,9 @@ public LogicalPlan window(LogicalPlan input,
     return new LogicalWindow(input, windowFunction, windowDefinition);
   }
 
-  public LogicalPlan highlight(LogicalPlan input, Expression field) {
-    return new LogicalHighlight(input, field);
+  public LogicalPlan highlight(LogicalPlan input, Expression field,
+      Map<String, Literal> arguments) {
+    return new LogicalHighlight(input, field, arguments);
   }
 
   public static LogicalPlan remove(LogicalPlan input, ReferenceExpression... fields) {

core/src/test/java/org/opensearch/sql/analysis/AnalyzerTest.java

@@ -27,10 +27,12 @@
 import static org.opensearch.sql.ast.tree.Sort.SortOption.DEFAULT_ASC;
 import static org.opensearch.sql.ast.tree.Sort.SortOrder;
 import static org.opensearch.sql.data.model.ExprValueUtils.integerValue;
+import static org.opensearch.sql.data.type.ExprCoreType.ARRAY;
 import static org.opensearch.sql.data.type.ExprCoreType.DOUBLE;
 import static org.opensearch.sql.data.type.ExprCoreType.INTEGER;
 import static org.opensearch.sql.data.type.ExprCoreType.LONG;
 import static org.opensearch.sql.data.type.ExprCoreType.STRING;
+import static org.opensearch.sql.data.type.ExprCoreType.STRUCT;
 
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
@@ -270,16 +272,41 @@ public void project_source() {
 
   @Test
   public void project_highlight() {
+    Map<String, Literal> args = new HashMap<>();
+    args.put("pre_tags", new Literal("<mark>", DataType.STRING));
+    args.put("post_tags", new Literal("</mark>", DataType.STRING));
+
+    assertAnalyzeEqual(
+        LogicalPlanDSL.project(
+            LogicalPlanDSL.highlight(LogicalPlanDSL.relation("schema", table),
+                DSL.literal("fieldA"), args),
+            DSL.named("highlight(fieldA, pre_tags='<mark>', post_tags='</mark>')",
+                new HighlightExpression(DSL.literal("fieldA")))
+        ),
+        AstDSL.projectWithArg(
+            AstDSL.relation("schema"),
+            AstDSL.defaultFieldsArgs(),
+            AstDSL.alias("highlight(fieldA, pre_tags='<mark>', post_tags='</mark>')",
+                new HighlightFunction(AstDSL.stringLiteral("fieldA"), args))
+        )
+    );
+  }
+
+  @Test
+  public void project_highlight_wildcard() {
+    Map<String, Literal> args = new HashMap<>();
     assertAnalyzeEqual(
         LogicalPlanDSL.project(
             LogicalPlanDSL.highlight(LogicalPlanDSL.relation("schema", table),
-                DSL.literal("fieldA")),
-            DSL.named("highlight(fieldA)", new HighlightExpression(DSL.literal("fieldA")))
+                DSL.literal("*"), args),
+            DSL.named("highlight(*)",
+                new HighlightExpression(DSL.literal("*")))
         ),
         AstDSL.projectWithArg(
             AstDSL.relation("schema"),
             AstDSL.defaultFieldsArgs(),
-            AstDSL.alias("highlight(fieldA)", new HighlightFunction(AstDSL.stringLiteral("fieldA")))
+            AstDSL.alias("highlight(*)",
+                new HighlightFunction(AstDSL.stringLiteral("*"), args))
         )
     );
   }

core/src/test/java/org/opensearch/sql/analysis/ExpressionAnalyzerTest.java

@@ -8,7 +8,6 @@
 
 import static java.util.Collections.emptyList;
 import static org.junit.jupiter.api.Assertions.assertEquals;
-import static org.junit.jupiter.api.Assertions.assertSame;
 import static org.junit.jupiter.api.Assertions.assertThrows;
 import static org.junit.jupiter.api.Assertions.assertTrue;
 import static org.opensearch.sql.ast.dsl.AstDSL.field;
@@ -38,7 +37,6 @@
 import org.opensearch.sql.ast.dsl.AstDSL;
 import org.opensearch.sql.ast.expression.AllFields;
 import org.opensearch.sql.ast.expression.DataType;
-import org.opensearch.sql.ast.expression.HighlightFunction;
 import org.opensearch.sql.ast.expression.RelevanceFieldList;
 import org.opensearch.sql.ast.expression.SpanUnit;
 import org.opensearch.sql.ast.expression.UnresolvedExpression;
@@ -50,7 +48,6 @@
 import org.opensearch.sql.expression.DSL;
 import org.opensearch.sql.expression.Expression;
 import org.opensearch.sql.expression.FunctionExpression;
-import org.opensearch.sql.expression.HighlightExpression;
 import org.opensearch.sql.expression.LiteralExpression;
 import org.opensearch.sql.expression.config.ExpressionConfig;
 import org.opensearch.sql.expression.window.aggregation.AggregateWindowFunction;
@@ -592,12 +589,6 @@ public void now_as_a_function_not_cached() {
     assertTrue(values.stream().noneMatch(v -> v.valueOf(null) == referenceValue));
   }
 
-  @Test
-  void highlight() {
-    assertAnalyzeEqual(new HighlightExpression(DSL.literal("fieldA")),
-        new HighlightFunction(stringLiteral("fieldA")));
-  }
-
   protected Expression analyze(UnresolvedExpression unresolvedExpression) {
     return expressionAnalyzer.analyze(unresolvedExpression, analysisContext);
   }

core/src/test/java/org/opensearch/sql/analysis/NamedExpressionAnalyzerTest.java

@@ -8,15 +8,14 @@
 
 import static org.junit.jupiter.api.Assertions.assertEquals;
 
+import java.util.HashMap;
+import java.util.Map;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.opensearch.sql.ast.dsl.AstDSL;
 import org.opensearch.sql.ast.expression.Alias;
 import org.opensearch.sql.ast.expression.HighlightFunction;
-import org.opensearch.sql.ast.expression.QualifiedName;
-import org.opensearch.sql.expression.DSL;
-import org.opensearch.sql.expression.Expression;
-import org.opensearch.sql.expression.LiteralExpression;
+import org.opensearch.sql.ast.expression.Literal;
 import org.opensearch.sql.expression.NamedExpression;
 import org.opensearch.sql.expression.config.ExpressionConfig;
 import org.springframework.context.annotation.Configuration;
@@ -40,8 +39,10 @@ void visit_named_select_item() {
 
   @Test
   void visit_highlight() {
+    Map<String, Literal> args = new HashMap<>();
     Alias alias = AstDSL.alias("highlight(fieldA)",
-        new HighlightFunction(AstDSL.stringLiteral("fieldA")));
+        new HighlightFunction(
+            AstDSL.stringLiteral("fieldA"), args));
     NamedExpressionAnalyzer analyzer =
         new NamedExpressionAnalyzer(expressionAnalyzer);